login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139849 Primes of the form 10x^2 + 10xy + 13y^2. 1
13, 73, 97, 157, 313, 397, 433, 577, 733, 853, 937, 997, 1153, 1237, 1657, 1693, 1753, 1777, 1993, 2113, 2593, 2617, 2677, 2833, 2917, 2953, 3037, 3253, 3373, 3433, 3457, 3517, 3673, 3793, 3853, 3877, 4093, 4177, 4273, 4297, 4357, 4513 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Discriminant = -420. See A139827 for more information.

LINKS

Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi]

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

FORMULA

The primes are congruent to {13, 73, 97, 157, 313, 397} (mod 420).

MATHEMATICA

QuadPrimes2[10, -10, 13, 10000] (* see A106856 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(6000) | p mod 420 in {13, 73, 97, 157, 313, 397}]; // Vincenzo Librandi, Jul 29 2012

(PARI) list(lim)=my(v=List(), s=[13, 73, 97, 157, 313, 397]); forprime(p=13, lim, if(setsearch(s, p%420), listput(v, p))); Vec(v) \\ Charles R Greathouse IV, Feb 10 2017

CROSSREFS

Sequence in context: A300028 A322478 A107141 * A139911 A097460 A138353

Adjacent sequences:  A139846 A139847 A139848 * A139850 A139851 A139852

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 02 2008

EXTENSIONS

Corrected and extended b-file - Ray Chandler, Jul 29 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 1 10:33 EDT 2020. Contains 333159 sequences. (Running on oeis4.)